I believe that it is petroleum ether.
Here is the answer. I am not sure how to explain it! Sorry!
Answer:
An emulsifying agent is typically characterized by having <u><em>d. one polar end and one nonpolar end.</em></u>
Explanation:
Emulsifiers are substances that have the ability to bind, for example, fats with those substances that have mostly water in their conformation. In other words, the emulsifier facilitates mixtures of two or more immiscible liquid substances.
This is because the molecules of an emulsifier are often lipophilic (attract oil) at one end and hydrophilic (attract water) at the other. In other words it consists of a polar (hydrophilic) head group and a non-polar (hydrophobic) tail.
<u><em>An emulsifying agent is typically characterized by having d. one polar end and one nonpolar end.</em></u>
Research for alternative energy sources have been positively affected, because of other reasons (excluding those EliteAnswers listed), such as:
1) Renewability: This means that resources are replaced as fast as they are used, meaning that they would not run out
2) Cleaner: Most alternative energy would not have the effect of polluting the earth after it is used, and may be easier to clean (if even need to)
hope this helps